SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '948222c81875bac61ac1bb9ffd70c4c79223952c0d787855c27eb18989c3c02c' 
  AND token = '8CegxGAhkwgXOG4cckshmEUpIThsVSa+U+PHjc08YLA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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