SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '46b77d4b613751a343fe9289ada1dba1f6e14e3b8cd6b991eed93b84c29c5a93' 
  AND token = 'J/FcCO0+3ZQyh8jgORtzxV5VeKH414vaowYtwb37IIA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}