SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f7ac1811f668f71eb5fc87bd8eadc243f16199cf06dccdc02b9d9c32a813d9a3' 
  AND token = 'BuIwSnoVptjfBTZ5mEXFKffAvKuFJy7T+bf7LoH47Qw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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