SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0214ddf03367e5ece622d0dac1517deb9845f851ce0ac3817aab9f467d226377' 
  AND token = '9F2RF5pXKZudFYxHqwEIhGoGU6yBSIjeL47so+BZzhk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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