SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '98bd199c07937aef5b244cdf177aeb4b741a3cd316dc8446ab6fafaf9cd0b802' 
  AND token = 'MU6aovCMp9U1Ha0Qg74wlcZUQbrdMIWhbryiaI30FcY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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