SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '41115aa371915a48d85b450644fde85d9c1a0f89cba439e86a55f6e0d8ac1b44' 
  AND token = 'xZbacRVENFN+6B5LGq4QUKEb+1ykZzJfrY8lXPzzLE4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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