SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'b938adec630179bac94698593f8d8cd45d478625fadc084fa091d9f181f2ec0a' 
  AND token = 'XHBzu/bi46h5ycJM/hjCLALdaJHW0Ku57DRwvj8qLVM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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