SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd981196feff767ac9c287b08e65b77f89b269a90a30b536b4039595838a82ab1' 
  AND token = 'uDksTIlB45BykE8D+hdvZC/2uFcklVAnw9v4u0MgqtA=' 
  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"
    }
  }
}