SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '207b4c1213aa302b45c2f4e036abda9b8d638de749a2f9281a4824c5ffcfe2d1' 
  AND token = '2nouZhNmOqzfcTa+Zv7Psue5YS/QgljzCdxU5nOX4fA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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