Sandbox

SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '3d624531838268d4962d24017626b4e809d304ee0efebff3af9685bce36b4fdd' 
  AND token = 'Qqq78QWHpMK526zz1fc3YMWMubyiK70Dvqmz4+7i0nk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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