SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cc1ed2d2db5d115c0dd10adef31867d8e3dcc606309283395e4946b892d971d4' 
  AND token = 'nvU8qn5YMtjUal/LylSgVin/nw/6ttFMJIm+Z6tGXoA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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