SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '092dacaf8bec2e4b6d59d0a5cdb301753471e23f0b8096a437125e6860dd1175' 
  AND token = '/+VeBTabYmXabMjLf1ZhQINKjJABtEmG8L9KJg8pRjA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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