SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'acbdfb5a2772d39a591a6e169d21fe5844c4c99d4148c1896b5a342fdcbfe70c' 
  AND token = '7Tvi+AE+9V/CiTSJx2On56BnNj/d/ePBnqlX7h3JjXg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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