SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '23e2bf7195856b8cda28d3f380fa794eeaf85068dd231fbe4f524a4455a085c3' 
  AND token = 'VImF2Q1+okeNjxNzr5kgpXdOLrByMpeEshWIhMKfUbk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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