SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '9c09858c07d356b501e0e227176146990dd60de6db12673658bdff6849c308ce' 
  AND token = 'oPLQiPklNUJ/InLV07YZLzQHDxKVhEVv3Sud0H0VRcI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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