SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'be56f65b6da0541177d61260a22581032c5589361def99a3757559f81c51cdc3' 
  AND token = '5aG0fXr5hhyAo6xaNG07E7aXJ8TGkXfRcPSR9cSrWcY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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