SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e90085413d0ffa5308cc22fe7788c8128e8a6eab06f75c8c240fc304428f407b' 
  AND token = 'scZTzcshAqAEbRQ9vNHXxgSZoHGuTnTaLilSypwCUQI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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