Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3aa14b0673294810eab5376b4a34685b69abfeae974cf672b3896c1389301947' 
  AND token = 'gK4IgMLUZ8QomOVyNKbJfhULI1tELnfX/pVbaJfeR9U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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