SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'f1478088321b6a08d2b44443654a9b5c1dfa645226a5bc5c5118f511598ec883' 
  AND token = 'wq0xIRxI2hsT5cPiS21UD+BpZkh4eOKtB/x9HX6IUK0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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