Sandbox

SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '5165313945f81478ec540ba16a8a2dafda8e7cd848e264c450388d7474a487f2' 
  AND token = '0qDvB6clnifvujTmCRc6E1gyziKfzSzLnrnU706ZDYE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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