SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a4f9d664696b8af416f32937fc4f1a4f01cc9ceff2d1c377a7fb2b325e5955de' 
  AND token = 'YG2+VRw+Ryujagkpr9TzILGwnMNAOKU+gii1/U5AXhE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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