SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '327f89fd445c2c9fad79632b8fd12b6ba0c02e60fb16159544bf9e3eaca34f12' 
  AND token = 'kqpHvFqKmqQo7DOhw2h3cjLrTzvUSB7O0hn+cJc+e00=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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