SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0388077bda471c35ff7dde30aa0eb2202ceec2274800cbc5302d9e1c460be245' 
  AND token = 'xAOxy1Tpig5L6vLcqJWZz8AkiQLa39/7+7VuPrpfhfs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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