SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '01e81054afa2fa7c11223b932d785df129b5cd2d81195c486643d9baa948c591' 
  AND token = 'tj1zyb1z/+V39gudsa2QzSW6VwIucD2Y+mIKuawkr5o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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