SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1663b68e3a6d083e142d284ef28e4450c40efa2ba92617caba5b97ab347a42db' 
  AND token = 'hiK6lVj/U+otCsvq/v1vXp9RcARphqopxxLVslaPh+Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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