SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7bf1273b3647385a759572469f957b8a9c614de647a4c2e07909fb81a2e65a71' 
  AND token = 'wvImDzoeFhzwyTebhqHz1/pgYTAivVJCg1iL8xXv+KM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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