SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2fb663e0a9f206ccc0462800c8cc29423cfb8b29075560a096e47b19177a08e4' 
  AND token = 'NOXm1gHSzJMwdWVgAGCGR34MyDiHZgJnV5+E4g021jo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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