SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7b5441dea0dccf3ea8ebf536f054223bf0d2d476da368dc122671572501e905b' 
  AND token = 'hlE7HdJfUTBR4Hr8X1F/bN8g+wuhF3qWQ/JO0873Hjg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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