SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '57253c35a608500f7955fad33ea528c71242f65dabcee0e24f1617f060ab2800' 
  AND token = 'EoaxCMIOdF9iH8cy6GNaRfSUJ0KUKxU+1n8mT53tww8=' 
  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"
    }
  }
}