SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8bc802ed71f3dd00a2478ff380c969e3501faf10e3bd41e4c6755012186022ea' 
  AND token = 'f+YMEMuKgeuTVLcl9wHyFwx4JhJ42kC/P6gSFzV1SZg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}