SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5d885a949525af114b007f36e0ae61f3668c1f2a508b8a6778687af52baab505' 
  AND token = 'l/lBVJEAvLiJLz826KQ9YZxNSHj/y0EtbUu+vByJoM8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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