SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd49d9fd89c1f595f1d3712b7ad645d07d60647d13465331b3f355da5f9cf9c00' 
  AND token = 'ldxDnSoykeifkhwvBDwdR1lRGLW24AAerHtQVagss0U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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