SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f4bb96771669778b7eb38e1af5b19a7f7e6de476a00fd6c2404fcef57ae4e63b' 
  AND token = '+yAJFznh/PZgm6UwwIVxbcBOUStol7c8w0/qjRb/UJs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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