SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2882ffc0dc7940d2d07a66035e9e211213ddc8e7b4d1b213653184781c71af32' 
  AND token = 'vwknCOncwOYCSb0aloqAil0pejjGXfToHoiL+SebKYw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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