SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '0d377f35131369f2fa32f920ff154baefbda93172938866d6e912c27635e6a9f' 
  AND token = 'UYRH8/yZKQwlgJJ0hWIjy3us6Du2G7Oe8E3HMvIOBGA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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