SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '167d229c23e04d5150a3ac65879db41b2366783b95e62e7654b2c1f0a7b033ca' 
  AND token = 'H9/iKJRySXuyoqSqTOEOJeGARwN1hVO8zmjTcEznrxs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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