SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd5ee8a0efdf62069f68eaf76fb062e23235486588fbf3cb39cc7592e0bd69f5d' 
  AND token = 'lVvXF/Gi3Z6gcdcB9jtQoiPuNXQNhh6LHY0zkmv+1LQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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