SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9c51d3a0ad673ad0227588ee10e1f0afd39a07b588e3ae1abf62d7750a8de39f' 
  AND token = 's2jpsnipGmAK7Lmzf7gZy6iiJiwSQLWx7KuLXkZnptQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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