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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '66092da6739628597b74cacda15f9cb7b1bcfddbbc1037418e25d382a5a35ecc' 
  AND token = '0cM2+ycy27HVTTByTA4visABNKU2FA2NM6FEicRjnCU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}