SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ae305f166d26cab341fa673d1ced1fbe4b321e466edc2afb1951a50d33a312ae' 
  AND token = 'RncoQF7febloXQPqpWfP3GDEOAd6IHc1tJEpOhiJIV4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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