SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '40a4b511f1119af9e987ce6dcbeb45de142872d80c5d7a162ac6be67ef97dc4c' 
  AND token = 'jVJ6FCdj00s3wl11nbfm0ymDzLyR6inz8/4je2DRsiA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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