SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '92edaa4997f36ddb02310800ec72a23489566a06592784e813e51315d9f650cd' 
  AND token = '6yYT9zAIlKi5SEUNY2BizZdbcZjajQXYr5QDEI9phUQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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