SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c648efb30490722eafc28bf62ca0b27a1cfce47fd1d7446a12d19e56a9daf1a4' 
  AND token = 'GKAJbs94Wc0LEjG816vnlW38CkFpxpM2CoD4SVGT/Cw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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