SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '1ec976e729498d8fb38ee24dd0ce13ba6d909315dc54660aca9519db8aa947b6' 
  AND token = 'oPpNDAluQ4yEKZP1e4q8YksKL0/vGgbt/WiqezUB02c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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