SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '8368bdc452a928dbceef970ab2eae8606ad5a1386c3e33ce8c361707fc708b6b' 
  AND token = 'LTnAtXwHGrxvrKWNlElp08O0GBZS6xLStEiNEpoH/Uw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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