SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'c485a3f107d128d32e52f3b2771c5088d6659a3d35ed022b0b328068b6507a60' 
  AND token = 'KfNBRiV+gjDtD552LTAtNj9rdIJk+Ud6l98C/8XCb2A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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