SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'af4c037bc5cf5b1f54e289a91c272d8948a602d88eb533ae51b315042ffcf63c' 
  AND token = 'nK93BP7DJJt/gyEGbk4Zm3LdBkUr7riROnRYLVSargw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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