SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5316a27de0d1f0208275b77da66f461deccdc9951f191707dbddd80309474adc' 
  AND token = '4j8Ke1+5gd8oxxRpEyYRIpiqwGbD2h2JgT97jcySVgk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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