SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '473b6f2b02838e72d12bc047304d4843d42298b6f10a6c566636c1c11dac0c71' 
  AND token = 'ai5N+7mDgdPsq7IPOPq80hEgOVmjPX48JQNJWnHsC3M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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