SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f5534bd6235d4f170b2d2faa69eff0864f1df9c11221110aa200628eca4aa423' 
  AND token = 'Q+AUdXaVG4jiYzHndBwFuZuW0r5+LXKEwax7/q6Q8JU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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