SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f30be84bc210ab8de8b29234b1f7a8c38de3718bee9bfbef636cba37589676c9' 
  AND token = 'breN9j3uQ2bMcv0RsnbI8Pkk+HzGwfbBTz/qjvU1xDE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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