SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dcbe1c3fdbb3ffab4645a588db58589e58774309395ee38952060673b08b1776' 
  AND token = 'Jdm+XETUwP0GjooSTSAZEOy0BT5OAxNPDNz+rNcYEog=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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