SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4d4ae461b300277ecdfe99386816f1a9ba51d16a80b708275e3c059aa43759c4' 
  AND token = 'W4ftDHadLxBVMDW5pq8a8AdDAPoPU0006XcMlHD/mtg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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