SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '0cfeb2770394254c21aabc8ac03609d0e5ca53399854e23257ecefcd288ff5b0' 
  AND token = 'XTGNrYzKbbkJlaGDJKD+woleAlS12nmyXZiV9DuRb8w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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