SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f1a3db32d99add3c9efcde1b12ae3267c967996edb74ad6c31d79b150a8d1a1c' 
  AND token = 'ybq4/4KJ3luNjrplcqtx1Y7y4XYk8GiM+g5OYMxD9JA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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