SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0efa1c8f2aef8be2d87f6e552a1623cc7bfe13fe3cd228b815da0ae3e00fd1dc' 
  AND token = 'q1tMW/UnBfR96WAShFbhv+OknnVMQFOOQQb6h4b6H+c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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