SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '42672145be1bba329a1e2d42aa94a6960a0d329cf2aa39ef2d05ab365b2f9159' 
  AND token = 'h1ijhGNeUIx6qiko2jfYRhXdZ7h+Q/Q/2nthJn9JlH8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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