SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd42e1fc0c1f3fddbf420b932b3e9ddb3043e1c6312b286f5386aa93510fa8057' 
  AND token = 'onb5r3sZU6RWDGOS3afDJ5Hv0oIN1CAvrCusEi4MAZU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00219

JSON explain

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