SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '927d4df9c6815f574b8e987c9074331eaf30601854228f72d2e5f88487503e38' 
  AND token = 'u7KO9DTSCVexz2Z+F9ithk3RzGGS9JvZ9c2rP5fOt4o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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