SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1779f7424915ce5431ae5c8288efb9e64899d6395550546b703719fe8e8f5ccb' 
  AND token = 'FenYzQLRQbCxQzKLv4wZap+Ij+f/Y3gRTPNLUwOhfis=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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