Sandbox

SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'b18122f30e4e82c1f3a55ee6e8929ecd573fa8be3ed63b7c295c2b4256929926' 
  AND token = 'N5cOkcKDWp8bs//YcGKKn0ombZrEIMPjBNddmTZbG6Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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