SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd6970260ca64b8d692ba455c3501257fa2a58f08a3464d6229759937d21b5e67' 
  AND token = 'H8p/KIUy0Qoo6IHnKLxZjU6gTC1QMK340+uqDBDHRmA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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