SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '30a4eda2728e17aaeb0b800279a26ba855d9d7eabca74a935756356b542f5bfd' 
  AND token = 'kHT1zSXWyXqyrrS5pibqh5IGRAkXNVinD+LmrOtx1v8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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