SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6652f5bb8c4f04d7024825fffc56b261ea3cb57283fd116c0c1850a77c6e9988' 
  AND token = 'DduUhLflQYreHcx/RtGMWs2LNEmsIHOVCQN7kDvyB3M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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