SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9cf0f1f0c4e703103276aa08b6dfc0cd8a51dca74bb8bcfc49ba94051dd30731' 
  AND token = 'ljUdEKjZSILqi/AzLI2bNYuKBUhkwhvUl1H1PYM2VzA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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