SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'c7280632d0c800f137d1ded2045ddaf1c7a65c1fe4c99f599e500acb77498650' 
  AND token = '22Zp3A1gSbMO+nUlXqGTqrAdeA7u+giBdztZZX3OdUM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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