SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '82626dcc85a76b8ba595d9577e3909f2a349a783e99778f36fa5dc553117eda7' 
  AND token = 'YWR4Z9nDjTGRxjrtBxc6oIMHZW6PoL3A8o/p+nyFqsg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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