SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f159f6220258600e04d61c8917305e5069be3ece77e4b0de407993de063146e3' 
  AND token = 'qzAbGhpDDGP4c5E/8WzhIBk+6jKWKLaRroG3eX4WUWw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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