SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0b5fd4ad484aa2d3b21dae4625c1f8380f36548812e3b0614efd39f62f789f8d' 
  AND token = 'IYRy2uHE/DHK6BXDwKR1iEgEXKz+cJoWxuiG/jXThTY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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