SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '17271ca000032d6dd44e001c54b978f2f0946df374b118d37feb914c5f56e398' 
  AND token = 'bcIm4NU5lTdiT5vnN3AmUG43lOJj+XVYycTFVpmFikM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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