SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '17798c375874874111ce62bb0330c5516482a23dc322b1ed08b918144f45d15a' 
  AND token = 'DnaTxjfvPFJVseNbn1L2P0etBs85bzanPDiW31BgJmc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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