SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3882a955f752e8f0d5d554e5797b18dab9b46ce6d8e62a3446a8c8f238c874eb' 
  AND token = 'y6H168FIpIXPI1iTBhAQAeKJwczrUsRSxKuWmODLtOY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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