SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dbfd4fb94f30987ef00aec12232541c2fc73e7bff1484f7633a9f44545a2d92e' 
  AND token = 'nem4Ow6ZQveLIaow+uXONBYw5dC6BHgQI33CNjKpZVw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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