SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8322875abaa10941e6c5ca9b58f2169f5a3cd9ace655711845cbc4c896a08cd1' 
  AND token = 'gIlFXtrDfu42N0cEmWqMiGj0Zwd1wgnGkmMy9sIteyw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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