SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '497530e9067b68024805dff1268ea16d297ffa98031092b342e3695a675520ff' 
  AND token = 'DzBSmqKoM1ZeogW3X5gaLsxIQxNmlOWR3seegnJJV3g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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