SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1604d14d4dd3385ffc0030f88c261023bf6f3ce5a16663943027b7d5ed26a99c' 
  AND token = 'oqpDClWZuhp2gQ1XOzmOFbIo5WGcbviPRJUq/YgkQBQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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