SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0aebbb203461dda7fa76e47bdce270f4129c11c4160a2082995c14ddd02a79c9' 
  AND token = 'kX6Hci6vfpBmk/9Vt+jGyDnY6J68yVlFxsa/mIO1JF4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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