SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '482b15d2eb111febd983b210a98705b0041f36b2ba902d66fbeabd3545ddec06' 
  AND token = '9g/WrBIhqmGuUkykaXwXylWRfHCFgTejgDwrbp6Xf/U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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