SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ef5d7031f3a6e31b746f2c2ef29209ee793fbf13f72627371780baf32d74ad7f' 
  AND token = 'LjbfML63nC0xedQ9qweYbp8zm6agxgR5uKJbqU7fMnA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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