SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e5a8674fcfb7c7743ed544aa40753318bd020973cf03be77df932fcd431aedbf' 
  AND token = 'd2kzgkqI1d6mVvVTIAZ/8A9pqohE/ERplVfgACncLXc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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