SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '2322884ab1c946f1b09c5700e6828c9a2a7d75b15ae67c8bda5fc19d886beab9' 
  AND token = '/RuHYM/k5Qum+NjUmLIeqp7m/3HGek+rZTeyxIqkch4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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