SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '09c5435c7dd2e66f6c8a833bd56e22e79e9a2b10f277bd9ac73e371a09ad724b' 
  AND token = 'bv/YlTQMzsvWYt/hR8Qno/LpFkYp0Ra8skBPtuWmgG8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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