SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8e5b912dea1a2b24c29790e394b387ef11205d4655a7ff8b24f5f7c38f4d1bb2' 
  AND token = 'hIFwKpWhVUSbECXbFZyRZP/9HuA0YGqlRIketRwQSZs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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