SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '17aacbc417bfcb12fc13b19090646e7d6c7fa7d8edb5356fd16b324e75bcb95a' 
  AND token = 'eJpKOpeiqsPECZbB1+sAEiQu35/YMGy5PI0zey2Xlsg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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