SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd267507b6b51f04be399d002cadc7a23bb210115dd381e0d2074d7cdfbff0430' 
  AND token = 'gbXnhMkUxfYE96On2ix8Eyeb8uNCbTXRDDaAxzNCaug=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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