SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4e2255867ceed4166fa22d55fb28c5f222129b2b53fb35333c6dd3b9dd61091a' 
  AND token = '1oYvycsz8mDnyGgyMxt7gUQeyyPZbpOo7QJ2RNxPzaA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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