SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd68e541bce7498c6f70abe8fd35883b611582e337f9e9216f56c3dc34bc08374' 
  AND token = 'RXqbQTXhmhxRmNtoP+Yw3nJS6M9ozoai4+mCG/uQeFM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}