SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '641436b057e8558e7ff5f992d05a3416c1ee7e206226ebf1c99503991aaabe57' 
  AND token = 'C3ZY9K1V3rxJZ0sgesTUlhAABFTG4QMNpq/g7J3d2mo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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