SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '1878cca219116a76f6fb39f44fe0d9ce2f5b895c2a8d6c7cc0c06b5d753f265c' 
  AND token = '8Q5sY3/Xu0i2Pa0sVvWQWswVmOCSckf/gqh0LtVCD+k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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