SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e0b2b1ca0ed9f4fa43868cd8bb925e8a54b313d1fd9a7de9922cb2f8f88583e9' 
  AND token = 'xM9i9eZBRav6yHdT6jKOXRxS26n/UG4RI1Vr6aol6V4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}