SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e2d1b33fc68f243ff21f769d8416a2cb4225a6456fc07932ddf0cd2b7c1e9394' 
  AND token = 'eW+VPC5Lqkj41HseJPY0B+B16iz5j0BCZ+8zzMgtTNg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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