SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4114cb0e62705caa8b6b9af5c199cd22d5158cddf36d2b70e1bdbe9e39cb5411' 
  AND token = '2/fZEA79DJYBBRDcjK/g29HbX/pXHVBonYQv3c5oepA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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