SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '224abc253e2c83e06f756a9e544c63098a6fc019749abb3636bf88ac5018d197' 
  AND token = 'KznsbY4WsZ24eUw+idtX3mjXSDL/VkYsJOtr27qn1VY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}