SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '02a54f7430a481598034a65316a2a32fc0b59476183bb57d83f42c8127df6386' 
  AND token = '4hRyyKUyExkC68UpGck7rGAHjw/U35EOfe7+2MAUupA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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