SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd98f084d8ecd1da0209db8b0056488fb4a54e1fa59b0efc72133d1a875d77a68' 
  AND token = 'saX/vvcGO/xdm+UJn6LhF9d4SDpAnz072G6g0h+HtKw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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