SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '364a240ea80f66c5e39da4610d9f3192605f75cc183b073bc04e7a2ad5fb54cf' 
  AND token = '4ovvuCTR7QQXx8iIKMpxqelYnDaKQykwlI3w+Mmo7dM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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