SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9b82abb0f3244fd90383fa88e625d1ffd01580c4a3df5b4b6f621dab41a77293' 
  AND token = 'lqK9qNJ1AQqKrq6c4oCGHViWZOb+8muZS+ubbVPDgOY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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