SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ad226f4b7c37c2a9360a4f54ca2956defbc9126c95b73180f9f670cb88567754' 
  AND token = 'ag6cz+IGGaK5/VNvbRg+TcqRIcK8wEApagu6/lKZF0Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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