SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd5ccd3eb9fb225778c1c787a5236579345c0b60a80dfd0aa24f04a7e4a9d24b8' 
  AND token = 'hBFpXAR6PvWHwjxsabrJwfDJIO9Ch2UiZQp6eeA5Kak=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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