SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cfdb92762e56639c7223d24fa58c13b2c0910f5719291e8541954e65a679176b' 
  AND token = 'Q61MXTXXjk3z7+GwJw/WhyvVfPXgQLr2nFMxyAqnnxg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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