SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e30a9c892dd9232e1e850b43792017b1b6274967c2d94d373a41c0ecf7d44d1a' 
  AND token = 'TczlI6QCy/zqXWLh/g8RRFj4B4kVbbpEBR0B5Kjmwbs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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