SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b12d105011b1e07804962899409224ecbf94c1c8805029afe2dfb1c349413478' 
  AND token = 'w6Bq78ly3LucBJSNanYelhdAkOTfJZ2wQdJDxoXn+DY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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