SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6e614127f5ce5deeeab14a665ac88b5208d5c2e3c926cb30fa1e5c4fd0225509' 
  AND token = '49k00lPtqP5Gj8m7snKkjMKdYxSptk2Z6Wq7eP6fIXo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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