SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '059600d14430f72364d3d5c3451d72630e766d985a4f1111875093b284697a15' 
  AND token = 'cJkUngByGTUhP8UHATeaY7gs6wUIAKdZ93P1wkSroU0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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